From: Cesar Strauss <cestrauss@gmail.com>
Date: Tue, 17 Aug 2021 10:13:04 +0000 (-0300)
Subject: Fix activation of cancel signal
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fa266e2d2b5f4e84b10df1572dff4c946cd104d9;p=soc.git

Fix activation of cancel signal

As an active low signal, the conditions to cancel must be ANDed together.
Being active high, exc_o.happened must be inverted.
---

diff --git a/src/soc/experiment/compldst_multi.py b/src/soc/experiment/compldst_multi.py
index d47572b4..d7fcb89b 100644
--- a/src/soc/experiment/compldst_multi.py
+++ b/src/soc/experiment/compldst_multi.py
@@ -455,8 +455,10 @@ class LDSTCompUnit(RegSpecAPI, Elaboratable):
         comb += self.adr_rel_o.eq(alu_valid & adr_l.q & busy_o)
 
         # the write/store (etc) all must be cancelled if an exception occurs
+        # note: cancel is active low, like shadown_i,
+        #       while exc_o.happpened is active high
         cancel = Signal(reset_less=True)
-        comb += cancel.eq(self.exc_o.happened | self.shadown_i)
+        comb += cancel.eq(~self.exc_o.happened & self.shadown_i)
 
         # store release when st ready *and* all operands read (and no shadow)
         comb += self.st.rel_o.eq(sto_l.q & busy_o & rd_done & op_is_st &